In such installations known from the market, in particular freshly painted vehicle bodies, but also parts of vehicle bodies or other objects, are dried. Such dryers are heated by sucking, inter alia, air out of the temperature control tunnel and mostly out of tunnel sections which are short in relation to the entire length of the temperature control tunnel, heating it in a heating unit by means of a heat exchanger and feeding it back to the temperature control tunnel or corresponding tunnel sections in a circuit.
When drying freshly painted objects, the air withdrawn from the temperature control tunnel or tunnel section is laden mainly with solvent which is released during the drying process. Coating constituents released during the drying of the objects are also found in this air.